1. Technical Field
The present invention relates to an electro-optical device and an electronic apparatus. In particular, the invention relates to the structure of a supporting frame that supports an electro-optical panel either directly or indirectly.
2. Related Art
In the typical configuration of a liquid crystal display medium that constitutes a part of an electro-optical device of the related art, a liquid crystal panel, which is an electro-optical panel, is placed over a backlight, which is a surface illumination device, that is, planar illumination device, so that the liquid crystal panel and the backlight overlap each other in a plan view. The backlight illuminates the liquid crystal panel from the back thereof. By means of illuminating light coming from the surface illumination device (backlight) of the electro-optical device, the electro-optical panel (liquid crystal panel) thereof displays images in a variety of desired modes. A surface illumination device that is known in the technical field to which the invention pertains is provided with a light source (herein correctively referred to as “a” light source) such as light emitting diodes (LED) or the like and further with an optical waveguide board. In such a known configuration, light that has been emitted from the light source enters an edge face of the optical waveguide board that constitutes a plane of incidence. Then, the light that has entered the optical waveguide board goes out from the upper surface thereof that constitutes a plane of emergence. The optical waveguide board of the surface illumination device is set at a position that corresponds to the drive region, that is, display area, of the electro-optical panel in a plan view.
A supporting frame that is made of, for example, a white resin material supports, either directly or indirectly, the surface illumination device and the electro-optical panel. In such a configuration of the related art, the supporting frame fixes the plan positions of the optical waveguide board and the electro-optical panel in an overlapping manner so as to make up a single display unit. In some cases, a metal frame, which is made of a metal material such as a stainless steel, is attached to the rear surface of the supporting frame.
In the configuration of a supporting frame of the related art, a resin is adhered to partial region(s) of a metal frame that has a box-like shape in such a manner that the resin and the metal frame make up a frame unit. For example, a resin is adhered to the peripheral region of the metal frame and the inner wall thereof. A few examples of such a configuration are described in JP-A-2003-202550 and JP-A-2004-240239. Since this type of supporting frame is made up of the resin and the metal frame that are adhered to each other, it offers some advantages such as improved mechanical strength and easier assembly. Therefore, the resin-adhered metal frame makes it possible to reduce the size and thickness of the supporting frame with such advantageous features. The supporting frame provides a mechanical support to the constituent elements of a backlight such as a light source, an optical waveguide board, and optical sheets and/or an electro-optical panel at the white resin regions thereof. With such a configuration, the electro-optical panel can utilize light that has been emitted from the backlight in an efficient manner.
There is an increasing demand for a compact electro-optical device. As the size and thickness thereof has become smaller in recent years, an electro-optical panel of these days is more susceptible to the adverse effects of static electricity. Static electricity could significantly affect the display of an electro-optical panel due to its fundamental reasons. As explained above, the supporting frame of the related art provides a mechanical support to the constituent elements of a surface illumination device and/or an electro-optical panel at the white resin regions thereof. With such a configuration, it is hard to discharge generated static electricity to the outside thereof, which is likely to cause electrostatic charging. Therefore, there is a risk that the electro-optical panel becomes damaged and/or causes malfunction due to the electrostatic charging. In addition, charged static electricity becomes discharged when any electro-conductive object such as a finger of a viewing person approaches the electro-optical panel or when it contacts the electro-optical panel, which results in a noise problem.
Moreover, since the supporting frame of the related art described above is mainly made of a metal frame as a base frame material and a resin that is adhered to partial regions of the main-body metal frame so as to support the electro-optical panel and the like, it is likely that the strength of adhesion of the resin to the base metal frame is poor. Furthermore, it is practically impossible, or at best difficult, to ensure the positional precision of the resin regions. Still furthermore, it is also difficult to achieve a high rigidity (mechanical strength) of the supporting frame as a whole. Therefore, there is a limit to reduction in the size and thickness of an electro-optical device that can be achieved with the above-described configuration of the supporting frame of the related art.